The invention relates to an improved apparatus for conditioning an article, such as an envelope, having a bentover flap. More particularly, the invention relates to an improved apparatus for opening envelopes at rates compatible with high speed serial feeding of opened envelopes to a workstation.
In conventional high volume mailrooms utilizing document inserting apparatus, envelopes are delivered to a work station in opened condition and arranged so that sheets or documents may be inserted into the envelope. Thus the envelopes, which are typically furnished by the manufacturer with the flat folded firmly against the body, must be serially opened individually and then serially fed to the workstation with the flap bent back so as to permit access to the interior of the envelope. Conventional envelope-opening devices have worked well in relatively slow mailing systems, but in order to continue to meet mailing deadlines as the volume of mail increases it has become necessary to substantially increase the throughput of the envelope conditions apparatus,
U.S. Pat. No. 2,668,053 issued to Bach discloses a two-cycle envelope-opening device in which an envelope is fed edgewise in a first direction, flap edge foremost, along a curved path into abutment against a stop positioned such that the flap passes beyond a stripper plate and then in a second, oppositely-directed movement is fed past the stripper plate which then engages the flap and folds it back as the envelope moves by. This device works well at slower speeds but because of the paper paths which must be sequentially negotiated by the envelopes, any jams which occur normally involve at least two envelopes must come to a complete stop and then reverse direction during the cycle, the possibilities for increased speed are limited. A further nuisance in such prior devices is that two cycles must occur before proper insertion of documents into an envelope is re-established.
U.S. Pat. No. 3,162,435 issued to Rastorguyeff, et. al. addressed and solved some of the problems mentioned above by utilizing a different technique for opening envelope flaps. In this device a flap-intercepting nose of a pivoted member is driven toward the envelope body by the force of the lower edge of the envelope striking a lever arm of the member as the enveloped is transported around a transfer roller. The feeding movement of the envelope against the lever arm causes this nose to slideably engage and fold back the flap. While this device has also worked well at low speeds, it cannot be easily adjusted to accommodate the various thicknesses and stiffnesses of the envelopes available. An even more significant limitation has been found in that in high speed operation using such devices, instances have occurred where the flaps of envelopes have been completely sheared off, apparently because of the increased engaged force of the intercepting edge created by particular combinations of envelope thickness and speed.